Spring applied phosphorus loss with cover crops in no-till terraced field

Cover crops (CC) can improve phosphorus (P) cycling by reducing water related P losses and contributing to P nutrition of a rotational crop. This is particularly important in claypan soils with freeze-thaw cycles in early spring in the Midwest U.S. This 4-year study (2019-2022) examined the impact of CC monoculture and mix of CC species on P losses from a fertilizer application, and determined the P balance in soil compared to no cover crop (noCC). The CC mix consisted of wheat (Triticum aestivum L.), radish (Raphanus raphanistrum subsp. Sativus), and turnip (Brassica rapa subsp. Rapa) (3xCCmix) in 2019 and 2021 before corn, and cereal rye (Secale cereale L.) was planted as monoculture before soybean in 2020 and 2022. The 3xCCmix had no effect on total phosphorus (TP) and dissolved reactive phosphorus (PO4-P) concentration or load in 2019 and 2021. Cereal rye reduced TP and PO4-P load 70% and 73%, respectively, compared to noCC. The variation in soil moisture, temperature, and net precipitation from fertilizer application until CC termination affected available soil P pools due to variability in CC species P uptake, residue decomposition, and P loss in surface water runoff. Overall, the P budget calculations showed cereal rye had 2.4 kg ha-1 greater P uptake compared to the 3xCCmix species which also reduced P loss in water and had greater differences in soil P status compared to noCC. This study highlights the benefit of CCs in reducing P loss in surface runoff and immobilizing P through plant uptake. However, these effects were minimal with 3xCCmix species and variability in crop residue decomposition from different CC species could affect overall P-soil balance.

Epichloë fungal endophyte interactions in perennial ryegrass (Lolium perenne L.) modified to accumulate foliar lipids for increased energy density

BACKGROUND

Commercial cultivars of perennial ryegrass infected with selected Epichloë fungal endophytes are highly desirable in certain pastures as the resulting mutualistic association has the capacity to confer agronomic benefits (such as invertebrate pest deterrence) largely due to fungal produced secondary metabolites (e.g., alkaloids). In this study, we investigated T2 segregating populations derived from two independent transformation events expressing diacylglycerol acyltransferase (DGAT) and cysteine oleosin (CO) genes designed to increase foliar lipid and biomass accumulation. These populations were either infected with Epichloë festucae var. lolii strain AR1 or Epichloë sp. LpTG-3 strain AR37 to examine relationships between the introduced trait and the endophytic association. Here we report on experiments designed to investigate if expression of the DGAT + CO trait in foliar tissues of perennial ryegrass could negatively impact the grass-endophyte association and vice versa. Both endophyte and plant characters were measured under controlled environment and field conditions.

RESULTS

Expected relative increases in total fatty acids of 17-58% accrued as a result of DGAT + CO expression with no significant difference between the endophyte-infected and non-infected progeny. Hyphal growth in association with DGAT + CO expression appeared normal when compared to control plants in a growth chamber. There was no significant difference in mycelial biomass for both strains AR1 and AR37, however, Epichloë-derived alkaloid concentrations were significantly lower on some occasions in the DGAT + CO plants compared to the corresponding null-segregant progenies, although these remained within the reported range for bioactivity.

CONCLUSIONS

These results suggest that the mutualistic association formed between perennial ryegrass and selected Epichloë strains does not influence expression of the host DGAT + CO technology, but that endophyte performance may be reduced under some circumstances. Further investigation will now be required to determine the preferred genetic backgrounds for introgression of the DGAT + CO trait in combination with selected endophyte strains, as grass host genetics is a major determinant to the success of the grass-endophyte association in this species.

Ultrafast Suppression of the Ferroelectric Instability in KTaO_{3}

We use an x-ray free-electron laser to study the lattice dynamics following photoexcitation with ultrafast near-UV light (wavelength 266 nm, 50 fs pulse duration) of the incipient ferroelectric potassium tantalate, KTaO_{3}. By probing the lattice dynamics corresponding to multiple Brillouin zones through the x-ray diffuse scattering with pulses from the Linac Coherent Light Source (LCLS) (wavelength 1.3 Å and <10  fs pulse duration), we observe changes in the diffuse intensity associated with a hardening of the transverse acoustic phonon branches along Γ to X and Γ to M. Using force constants from density functional theory, we fit the quasiequilibrium intensity and obtain the instantaneous lattice temperature and density of photoexcited charge carriers. The density functional theory calculations demonstrate that photoexcitation transfers charge from oxygen 2p derived π-bonding orbitals to Ta 5d derived antibonding orbitals, further suppressing the ferroelectric instability and increasing the stability of the cubic, paraelectric structure.

Direct Observation of Coherent Longitudinal and Shear Acoustic Phonons in TaAs Using Ultrafast X-Ray Diffraction

Using femtosecond time-resolved x-ray diffraction, we investigated optically excited coherent acoustic phonons in the Weyl semimetal TaAs. The low symmetry of the (112) surface probed in our experiment enables the simultaneous excitation of longitudinal and shear acoustic modes, whose dispersion closely matches our simulations. We observed an asymmetry in the spectral line shape of the longitudinal mode that is notably absent from the shear mode, suggesting a time-dependent frequency chirp that is likely driven by photoinduced carrier diffusion. We argue on the basis of symmetry that these acoustic deformations can transiently alter the electronic structure near the Weyl points and support this with model calculations. Our study underscores the benefit of using off-axis crystal orientations when optically exciting acoustic deformations in topological semimetals, allowing one to transiently change their crystal and electronic structures.

Nutrient loss from floodplain soil with controlled subsurface drainage under forage production

Expansion of subsurface drainage into forage production may have a deleterious effect on surface waters due to increased nitrogen and phosphorus loading. The impact of controlled subsurface drainage (CD) on nitrogen and phosphorus loss compared with free subsurface drainage (FD) in tile drainage water has been explored to a lesser extent from forage production systems. This study quantifies the effects of CD and FD on average seasonal concentrations and cumulative loads of the total suspended solids (TSS), nitrate nitrogen (NO₃ -N), and dissolved reactive phosphorus (DRP) in subsurface drainage water from a poorly drained floodplain soil in a cereal rye (Secale cereale L.)-sorghum [Sorghum bicolor (L.) Moench] rotation with rotational cattle grazing. During all crop seasons of sorghum production (2010-2013), CD had 6.03-9.63 mg L^-1 less NO₃ -N than FD. Mean DRP concentration was significantly higher for CD than for FD during all seasons except for sorghum in 2012-2013. Average cumulative discharge was 38 and 314 m³ ha^-1 less for CD than for FD during sorghum and cereal rye growing seasons, respectively. Controlled drainage had 0.68-6.14 kg ha^-1 lower cumulative NO₃ -N loads than FD. The DRP loads were dependent on discharge. During sorghum growing seasons, TSS and DRP loads were 79-90% lower in CD compared with FD. The ability to reduce drainage water flow from tiles and subsequent nitrogen and phosphorus loading with CD compared with FD in a floodplain soil indicates that CD can be effective best management practice for forage production systems.

Urea Nitrapyrin Placement Effects on Soil Nitrous Oxide Emissions in Claypan Soil

Corn ( L.) production in poorly drained claypan soils in the US Midwest is a challenge due to low soil permeability, which may result in wetter soil conditions and relatively large amounts of soil NO emissions early in the growing season. The objectives of this study were to determine the effects of urea fertilizer placement with and without nitrapyrin (NI) on daily and cumulative soil NO emissions, and yield-scaled NO emissions in 2016 and 2017. Treatments included urea deep banded to a 20-cm depth (DB), urea deep banded to 20 cm plus NI (DB+NI), urea incorporated after a surface broadcast application to ∼8-cm depth (IA), urea broadcast on the soil surface (SA), and a nonfertilized control (NTC). Fertilizer was applied at 202 kg N ha. Surface soil NO efflux rates were generally lower (<50 g NO-N ha d) during the first 3 wk after N fertilization and latter parts of the growing seasons. When averaged across the 2016 and 2017 growing seasons, all fertilized treatments had significantly greater (2.33-5.60 kg NO-N ha, < 0.05) cumulative soil NO emissions than NTC. The DB+NI treatment had 54 and 55% lower cumulative soil NO emissions than IA and SA, respectively. In 2017, DB+NI had similar soil yield-scaled NO emissions to NTC. Percentage grain yield increase over NTC was highest for DB and DB+NI. Grain yield in 2016 was 14 to 18% higher for DB and DB+NI than SA. Results suggest that DB+NI is an effective management strategy for reducing cumulative soil NO emissions and increasing grain yields over the growing season.

Observation of second sound in graphite at temperatures above 100 K

Wavelike thermal transport in solids, referred to as second sound, is an exotic phenomenon previously limited to a handful of materials at low temperatures. The rare occurrence of this effect restricted its scientific and practical importance. We directly observed second sound in graphite at temperatures above 100 kelvins by using time-resolved optical measurements of thermal transport on the micrometer-length scale. Our experimental results are in qualitative agreement with ab initio calculations that predict wavelike phonon hydrodynamics. We believe that these results potentially indicate an important role of second sound in microscale transient heat transport in two-dimensional and layered materials in a wide temperature range.

Single-bubble and multibubble cavitation in water triggered by laser-driven focusing shock waves

In this study a single laser pulse spatially shaped into a ring is focused into a thin water layer, creating an annular cavitation bubble and cylindrical shock waves: an outer shock that diverges away from the excitation laser ring and an inner shock that focuses towards the center. A few nanoseconds after the converging shock reaches the focus and diverges away from the center, a single bubble nucleates at the center. The inner diverging shock then reaches the surface of the annular laser-induced bubble and reflects at the boundary, initiating nucleation of a tertiary bubble cloud. In the present experiments, we have performed time-resolved imaging of shock propagation and bubble wall motion. Our experimental observations of single-bubble cavitation and collapse and appearance of ring-shaped bubble clouds are consistent with our numerical simulations that solve a one-dimensional Euler equation in cylindrical coordinates. The numerical results agree qualitatively with the experimental observations of the appearance and growth of large bubble clouds at the smallest laser excitation rings. Our technique of shock-driven bubble cavitation opens interesting perspectives for the investigation of shock-induced single-bubble or multibubble cavitation phenomena in thin liquids.

Use of an HBV-DNA Hybridization Assay in the Evaluation of Equivocal Hepatitis B Virus Tests in Solid Organ Donors

Context

Serological markers for the hepatitis B virus are routinely used in the evaluation of potential organ donors. However, serological tests can be associated with significant false or equivocal results and may not be indicative of the true risk of hepatitis B infection. Studies have recently questioned the significance of an isolated hepatitis B core antibody test in evaluating the suitability of solid organs for transplantation. The ability to detect hepatitis B virus DNA may prove useful when the diagnosis of hepatitis B infection is in doubt.

Design

Serum samples from 16 donors with equivocal or positive hepatitis B core antibody and/or hepatitis B surface antigen serological screening tests were retrospectively tested for the presence of hepatitis B DNA. Any available follow-up data on the placement of organs from these donors was obtained.

Results

One of the 16 (6.3%) donors tested positive for the presence of hepatitis B DNA, but organs from this donor were not recovered or transplanted. Follow-up on 14 organs recovered and transplanted from 6 donors in this group did not show clinical and/or laboratory evidence of hepatitis B infection in the recipients.

Conclusions

In our donor population, there was a low incidence (6.3%) of donors with equivocal or positive hepatitis B core antibody and/or hepatitis B surface antigen serological screening tests who subsequently demonstrated the presence of detectable hepatitis B DNA. Posttransplantation follow-up of the recipients of 14 recovered organs failed to demonstrate any cases of posttransplant hepatitis B infection.

Cooperative photoinduced metastable phase control in strained manganite films

A major challenge in condensed-matter physics is active control of quantum phases. Dynamic control with pulsed electromagnetic fields can overcome energetic barriers, enabling access to transient or metastable states that are not thermally accessible. Here we demonstrate strain-engineered tuning of La2/3Ca1/3MnO3 into an emergent charge-ordered insulating phase with extreme photo-susceptibility, where even a single optical pulse can initiate a transition to a long-lived metastable hidden metallic phase. Comprehensive single-shot pulsed excitation measurements demonstrate that the transition is cooperative and ultrafast, requiring a critical absorbed photon density to activate local charge excitations that mediate magnetic-lattice coupling that, in turn, stabilize the metallic phase. These results reveal that strain engineering can tune emergent functionality towards proximal macroscopic states to enable dynamic ultrafast optical phase switching and control.

Laser-induced transient grating setup with continuously tunable period

We present a modification of the laser-induced transient grating setup enabling continuous tuning of the transient grating period. The fine control of the period is accomplished by varying the angle of the diffraction grating used to split excitation and probe beams. The setup has been tested by measuring dispersion of bulk and surface acoustic waves in both transmission and reflection geometries. The presented modification is fully compatible with optical heterodyne detection and can be easily implemented in any transient grating setup.

DRD4 Genotype and the Developmental Link of Peer Social Preference with Conduct Problems and Prosocial Behavior Across Ages 9-12 Years

The peer environment is among the most important factors for children’s behavioral development. However, not all children are equally influenced by their peers, which is potentially due to their genetic make-up. The dopamine receptor D4 gene (DRD4) is a potential candidate gene that may influence children’s susceptibility to the peer environment. In the present study, we explored whether variations in the DRD4 gene moderated the association between children’s social standing in the peer group (i.e., social preference among classmates) with subsequent conduct problems and prosocial behavior among 405 (51 % females) elementary school children followed annually throughout early adolescence (ages 9–12 years). The behavioral development of children with and without the DRD4 7-repeat allele was compared. The results indicated that children who had higher positive social preference scores (i.e., who were more liked relative to disliked by their peers) showed less conduct problem development in subsequent years relative to children who had lower positive social preference scores. In contrast, children who had more negative preference scores (i.e., who were more disliked relative to liked among peers) showed more conduct problem development in subsequent years, relative to children who had less negative preference scores. However, these effects only occurred when children had a 7-repeat allele. For children who did not have a 7-repeat allele, the level of social preference was not associated with subsequent conduct problems. No evidence for gene–environment interaction effects for prosocial behavior was found. The implications for our understanding of conduct problem development and its prevention are discussed.

Reducing phosphorus loss in tile water with managed drainage in a claypan soil

Installing subsurface tile drain systems in poorly drained claypan soils to improve corn ( L.) yields could potentially increase environmental phosphorus (P) loss through the tile drainage system. The objectives of the study were to quantify the average concentration and loss of ortho-P in tile drain water from a claypan soil and to determine whether managed subsurface drainage (MD) could reduce ortho-P loss in tile water compared with free subsurface drainage (FD). Flow-weighted ortho-P concentration in the tile water was significantly lower with MD (0.09 mg L) compared with that of FD (0.15 mg L). Ortho-P loss in the tile water of this study was reduced with MD (36 g ha) by 80% compared with FD (180 g ha). Contrary to previous research, reduced ortho-P loss observed over the 4-yr study was not solely due to the reduced amount of water drained annually (63%) with MD compared with FD. During the spring period, when flow was similar between MD and FD, the concentration of ortho-P in the tile water generally was lower with MD compared with FD, which resulted in significantly less ortho-P loss with MD. We speculate that MD's ability to conserve water during the dry summer months increased corn's uptake of water and P, which reduced the amount of P available for leaching loss in the subsequent springs.

Lifetime of high-order thickness resonances of thin silicon membranes

Femtosecond laser pulses are used to excite and probe high-order longitudinal thickness resonances at a frequency of ∼270 GHz in suspended Si membranes with thickness ranging from 0.4 to 15 μm. The measured acoustic lifetime scales linearly with the membrane thickness and is shown to be controlled by the surface specularity which correlates with roughness characterized by atomic force microscopy. Observed Q-factor values up to 2400 at room temperature result from the existence of a local maximum of the material Q in the sub-THz range. However, surface specularity would need to be improved over measured values of ∼0.5 in order to achieve high Q values in nanoscale devices. The results support the validity of the diffuse boundary scattering model in analyzing thermal transport in thin Si membranes.

Intrinsic to extrinsic phonon lifetime transition in a GaAs-AlAs superlattice

We have measured the lifetimes of two zone-center longitudinal acoustic phonon modes, at 320 and 640 GHz, in a 14 nm GaAs/2 nm AlAs superlattice structure. By comparing measurements at 296 and 79 K we separate the intrinsic contribution to phonon lifetime determined by phonon-phonon scattering from the extrinsic contribution due to defects and interface roughness. At 296 K, the 320 GHz phonon lifetime has approximately equal contributions from intrinsic and extrinsic scattering, whilst at 640 GHz it is dominated by extrinsic effects. These measurements are compared with intrinsic and extrinsic scattering rates in the superlattice obtained from first-principles lattice dynamics calculations. The calculated room-temperature intrinsic lifetime of longitudinal phonons at 320 GHz is in agreement with the experimentally measured value of 0.9 ns. The model correctly predicts the transition from predominantly intrinsic to predominantly extrinsic scattering; however the predicted transition occurs at higher frequencies. Our analysis indicates that the 'interfacial atomic disorder' model is not entirely adequate and that the observed frequency dependence of the extrinsic scattering rate is likely to be determined by a finite correlation length of interface roughness.

Interaction of a contact resonance of microspheres with surface acoustic waves

We study the interaction of surface acoustic waves (SAWs) with a contact-based vibrational resonance of 1 μm silica microspheres forming a two-dimensional granular crystal adhered to a substrate. The laser-induced transient grating technique is used to excite SAWs and measure their dispersion. The measured dispersion curves exhibit "avoided crossing" behavior due to the hybridization of the SAWs with the microsphere resonance. We compare the measured dispersion curves with those predicted by our analytical model and find excellent agreement. The approach presented can be used to study the contact mechanics and adhesion of micro- and nanoparticles as well as the dynamics of microscale granular crystals.

Thermal conductivity spectroscopy technique to measure phonon mean free paths

Size effects in heat conduction, which occur when phonon mean free paths (MFPs) are comparable to characteristic lengths, are being extensively explored in many nanoscale systems for energy applications. Knowledge of MFPs is essential to understanding size effects, yet MFPs are largely unknown for most materials. Here, we introduce the first experimental technique which can measure MFP distributions over a wide range of length scales and materials. Using this technique, we measure the MFP distribution of silicon for the first time and obtain good agreement with first-principles calculations.

Demonstration of terahertz frequency-dependent field transformation in an irregular waveguide structure with direct measurement of the internal electric fields

We demonstrate irregular scattering structure frequency-dependent field control at terahertz frequencies by means of a TM(10) to TM(30) mode converter designed for operation near 300 GHz and fabricated out of lithium niobate. Imaging of the electric fields in the sample, with a Fourier analysis of the time domain signal, yielded the performance as a function of frequency.

Femtosecond pulse sequences used for optical manipulation of molecular motion

Optical control over elementary molecular motion is enhanced with timed sequences of femtosecond (10(-15) second) pulses produced by pulse-shaping techniques. Appropriately timed pulse sequences are used to repetitively drive selected vibrations of a crystal lattice, in a manner analogous to repetitively pushing a child on a swing with appropriate timing to build up a large oscillation amplitude. This process corresponds to repetitively "pushing" molecules along selected paths in the lattice. Amplification of selected vibrational modes and discrimination against other modes are demonstrated. Prospects for more extensive manipulation of molecular and collective behavior and structure are clearly indicated.

Optical generation of gigahertz-frequency shear acoustic waves in liquid glycerol

Picosecond laser ultrasonic techniques for acoustic wave generation and detection have been employed to probe shear acoustic waves in liquid glycerol at gigahertz frequencies. The experimental approach uses a unique laser pulse shaping technique and a crystallographically canted metal layer to generate frequency-tunable transverse acoustic waves, and uses time-domain coherent Brillouin scattering to detect the waves after they propagate through a liquid layer and into a solid substrate. A linear frequency dependence is found for both the shear speed and attenuation rate in glycerol.

Tracking the motion of charges in a terahertz light field by femtosecond X-ray diffraction

In condensed matter, light propagation near resonances is described in terms of polaritons, electro-mechanical excitations in which the time-dependent electric field is coupled to the oscillation of charged masses. This description underpins our understanding of the macroscopic optical properties of solids, liquids and plasmas, as well as of their dispersion with frequency. In ferroelectric materials, terahertz radiation propagates by driving infrared-active lattice vibrations, resulting in phonon-polariton waves. Electro-optic sampling with femtosecond optical pulses can measure the time-dependent electrical polarization, providing a phase-sensitive analogue to optical Raman scattering. Here we use femtosecond time-resolved X-ray diffraction, a phase-sensitive analogue to inelastic X-ray scattering, to measure the corresponding displacements of ions in ferroelectric lithium tantalate, LiTaO(3). Amplitude and phase of all degrees of freedom in a light field are thus directly measured in the time domain. Notably, extension of other X-ray techniques to the femtosecond timescale (for example, magnetic or anomalous scattering) would allow for studies in complex systems, where electric fields couple to multiple degrees of freedom.

Metrics for negative-refractive-index materials

The importance of loss in the field solution for left-handed media, and in particular, the impact on what would otherwise be a purely evanescent field, is addressed. Using an equivalent electric current source, field solutions are constructed in semi-infinite and finite thickness left-handed media. In the slab case, field growth and power dissipation metrics with uniform amplitude and uniform power excitation, respectively, provide a means to evaluate the potential of a left-handed material lens. Power dissipation suggests that field growth will be adversely impacted.

Evaluation of nutritional status in advanced metastatic cancer

Consecutive cancer referrals to a palliative medicine program were evaluated to assess nutritional status using a standard protocol. The study included 352 patients (180 men, 172 women; median age 61 years, range 22-94 years). The most common diagnosis was lung cancer. All had metastatic disease, 139 with gastrointestinal involvement. The most common gastrointestinal symptoms were weight loss ( n=307), anorexia ( n=285), and early satiety ( n=243). Of those with any weight loss, 71% had lost >or0% of their pre-illness weight. The most common factor identified which might have contributed to weight loss was hypophagia ( n=275/307). Men had lost weight more often and to a greater extent than women. Triceps skinfold (TSF) was measured in 337: 51% had values that suggested severe fat deficiency. Upper mid-arm muscle area (AMA) was measured in 349: 30% had evidence of significant muscle mass reduction. The body mass index (BMI) was normal or increased in most patients. Calculated resting energy expenditure (REE) ( n=324) was high in 41%. C-reactive protein was elevated in 74% of those measured ( n=50). We conclude that: (1).most of this group of cancer patients referred to palliative medicine had severe weight loss; (2).there was a gender difference in the severity and type of weight loss; (3).males lost more weight overall and more muscle than females; (4).males with any degree of weight loss had a higher REE than females; (5).a significant correlation existed between the time from diagnosis to death and the severity of weight loss in the prior month; (6).BMI was normal in most patients, suggesting precancer diagnosis obesity; and (7).both TSF and AMA correlated well with body composition of both fat and protein as determined by bioelectrical impedance.

Induction of donor-specific tolerance to islet allografts in nonhuman primates

Pancreatic tissue grafting is by far the most physiological therapeutic solution to the insulin deficiency of diabetes. Recent clinical trials have indicated somewhat successful use of nonsteroidal immunosuppressive regimens and a successful nonhuman primate trial using CD154 for costimulation blockade was reported. However, these protocols need to be replaced with safe and efficacious ones in which long-term allotolerance would make these treatments routine in a clinical setting. With the specific objective of testing whether peripheral infusions of stem cells or stem cell fractions in conjunction with islet allografting would induce allograft tolerance, we have established a macaque diabetic model. The macaques were rendered diabetic by streptozotocin and required daily doses of insulin to maintain lower blood glucose levels. The diabetic macaques then received islets and stem cells from unrelated and MHC-mismatched donors without any immunosuppression. In our initial analysis, 5 of 7 macaques that received stem cell infusions at the time of islet allografting have shown allograft survival longer than the group of macaques that received islets without the stem cell infusion. One of these five macaques has been normoglycemic for 10 months, with no exogenous insulin. This macaque received stem cell population enriched for CD34+ cells with depletion of CD18 cells, which have shown low or no allostimulatory potential in mixed lymphocyte cultures. Increased levels in insulin and C-peptide levels were shown in the macaques after islet transplantation.

Induction of islet allotolerance in nonhuman primates

Recent clinical trials have pioneered the successful use of a nonsteroidal immunosuppressive regimen and established a basis for application in a routine clinical setting. In this study, a single islet transplant was not sufficient to regulate blood glucose levels, and a second transplant became necessary. A similar observation was made in our macaque islet transplant study, where animals after the second transplantation have shown trends towards normoglycemia in the presence of mycophenolate mofetil. All five animals that received the second transplant have shown an initial rise in C peptide levels, which rapidly decreased as we tapered the MMF dose from 20 mg/kg BID to 5 mg/kg SID. Two animals of the five that were preconditioned with MMF one week prior to transplantation have shown significantly higher C peptide levels. We believe that it is very important to understand the relationship between the first graft failure and subsequent islet allograft success. Since graft success did not correlate with number of transplanted islets, the correction of blood glucose levels toward normoglycemia after the second transplantation suggests a mechanism by which the allotolerance to second transplant is facilitated by the first islet transplantation. These initial observations suggest approaches to "tolerize" the recipient to accept the second-transplant islets (a) through preconditioning the animal to improve the rate of success for the first transplant or (b) through tolerization to islets in the first transplant to facilitate better engraftment of the second-transplant islets.

A phase II study of methylphenidate for depression in advanced cancer

This study evaluated the use of methylphenidate for depression in advanced cancer

DESIGN

Phase II open-label prospective study.

ELIGIBILITY CRITERIA

No previous use of methylphenidate or current use of other antidepressants.

EVALUATION

Depression and response to treatment were determined by asking the patient: "are you depressed?" Patients were assessed at baseline and at days 3, 5, and 7.

TREATMENT

Starting dose was 5 mg at 8:00 a.m. and 12:00 noon. The dose was titrated for lack of response on any of the assessment days. RESPONSE CRITERIA: A negative response to the question: "are you depressed?"

RESULTS

Some 41 patients were enrolled and 30 (15 men, 15 women) completed the study. Median age was 68 years (range: 30-90). Methylphenidate was stopped for six patients because of side effects and five were not evaluable; 21 responded to 10 mg/day on day 3; the other nine responded to 20 mg/day on day 5, 29 maintained their positive response through day 7. Anorexia, fatigue, concentration, and sedation also improved in some. All who completed the study had tolerable side effects, none of which caused treatment to stop.

CONCLUSIONS

Methylphenidate is effective for depression in advanced cancer A starting dose of 10 mg in divided doses is effective in most patients. Dose escalation may be needed. Improvement occurs within three days. Close monitoring of side effects is recommended.

Important drugs for cough in advanced cancer

Cough is a defense mechanism that prevents the entry of noxious materials into the respiratory system and clears foreign materials and excess secretions from the lungs and respiratory tract. In advanced cancer, it is a common symptom that interferes with the patient's daily activity and quality of life. Empiric treatment with antitussive agents is often needed. Two classes of antitussive drugs are available: (1) centrally acting: (a) opioids and (b) non-opioids; (2) peripherally acting: (a) directly and (b) indirectly. Antitussive availability varies widely around the world. Many antitussives, such as benzonatate, codeine, hydrocodone, and dextromethorphan, were extensively studied in the acute and chronic cough settings and showed relatively high efficacy and safety profiles. Benzonatate, clobutinol, dihydrocodeine, hydrocodone, and levodropropizine were the only antitussives specifically studied in cancer and advanced cancer cough. They all have shown to be effective and safe in recommended daily dose for cough. In advanced cancer the patient's current medications, previous antitussive use, the availability of routes of administration, any history of drug abuse, the presence of other symptoms and other factors, all have a role in the selection of antitussives for prescription. A good knowledge of the pharmacokinetics, dosage, efficacy, and side effects of the available antitussives provides for better management.

Assessment of delirium in advanced cancer: the use of the bedside confusion scale

We conducted a prospective assessment of 50 consecutive admissions to an acute palliative medicine unit, using the bedside confusion scale (BSCS). Information including age, gender, diagnosis, and the presence or absence of brain metastasis was collected. Possible predisposing factors for delirium were recorded. Forty-one of 50 consecutive admissions were screened. There were 18 men and 23 women with a median age of 65 years (average: 60-75). The most common diagnoses among all were lung and breast cancer. Thirteen patients were delirious (BSCS score of > or = 2), 10 borderline (BSCS score = 1), and 21 normal (BSCS score = 0). Brain metastases and drugs appeared to be the most common predisposing factors of delirium. Forty percent of those that were delirious received haloperidol as symptomatic treatment. The BSCS is simple, portable, valid, quick, and easy to use by any medical team member. Delirium is common in hospitalized patients with advanced cancer.

Modern management of the cancer anorexia-cachexia syndrome

The cancer anorexia-cachexia syndrome is common, occurring in 80% of patients with advanced-stage cancer, and it is one of the most frequent causes of death in patients with cancer. It is a complex problem involving abnormalities in protein, carbohydrate, and fat metabolism. Tumors have both direct and indirect effects that result in anorexia and weight loss. The disease burden does not necessarily correlate with the degree of cachexia. In addition to the physical manifestations, the resulting abnormalities have a significant psychologic effect on patients and their families. Although there is no treatment to reverse the process, pharmacologic and nonpharmacologic measures can enhance food intake and improve quality of life.

Methylphenidate for fatigue in advanced cancer: a prospective open-label pilot study

Psychostimulants such as methylphenidate are used for fatigue in cancer patients. We report a prospective, open-label, pilot study of the successful use of methylphenidate to treat fatigue in nine of 11 consecutive patients with advanced cancer. Seven had received radiation or chemotherapy, a median of three weeks (range from one to 30 weeks) prior to methylphenidate. A rapid onset of benefit was noted, even in the presence of mild anemia. Sedation and pain also improved in some. Only one patient had side effects severe enough to stop the medication.

Music therapy in palliative medicine

A partnership between The Cleveland Clinic Foundation and The Cleveland Music School Settlement has resulted in music therapy becoming a standard part of the care in our palliative medicine inpatient unit. This paper describes a music therapy program and its impact on patients, their families, and staff. A service delivery model is suggested for implementation and integration of music therapy within palliative medicine. Specific music therapy interventions, evaluation and documentation techniques are also mentioned. A description of patient and family responses to music therapy, staff satisfaction, and effectiveness of interventions is presented.

Hydromorphone: pharmacology and clinical applications in cancer patients

Hydromorphone is a more potent opioid analgesic than morphine and is used for moderate to severe pain. It can be administered by injection, by infusion, by mouth, and rectally. Oral bioavailability is low. The kidney excretes hydromorphone and its metabolites. Some metabolites may have greater analgesic activity than hydromorphone itself but are unlikely to contribute to the pharmacological activity of hydromorphone. With the exception of pruritus, sedation and nausea and vomiting, which may occur less after hydromorphone than after morphine, the side-effects of these drugs are similar. On a milligram basis hydromorphone is five times as potent as morphine when given by the oral route, and 8.5 times as potent as morphine when given intravenously.

The gastrointestinal symptoms of advanced cancer

The commonest gastrointestinal (GI) symptoms in advanced cancer are reviewed with reference to definition, pathophysiology, etiology, prevalence, severity, and management. Observation or reporting of such symptoms must lead to consideration of the multi-faceted pathophysiology. Careful assessment and an analytical detailed approach are the keystones of effective management.

Infectious complications of advanced cancer

We present a retrospective study of the frequency, pattern, and management of infections in advanced cancer. Three hundred ninety-three patients were admitted to an acute care palliative medicine unit in an 8-month period for evaluation and palliation of cancer-related symptoms and complications. One hundred fifteen had at least one positive bacteriological culture, and 100 of these patients were evaluable. One hundred fifty-two infections and 192 isolates were identified. Sixty-eight patients had polymicrobial infections. Sixty-six patients had urinary tract infections. Forty-one were found to have multisystemic infections. Eighty-one had invasive devices; 32 had more than one invasive device. Fifty-three were taking corticosteroids at the time of infection. Only 3 were neutropenic. Urinary tract infections were significantly more common in those taking corticosteroids. The median duration of antibiotic treatment was 11 days and the median hospital stay, 14 days. Twenty-eight patients died in the hospital; 10 of those who died had lung cancer, which was a statistically significant observation. In conclusion, infections are an underrecognized but common complication in nonneutropenic hospitalized patients with advanced solid tumors. Urinary tract infections appear to be associated with the use of corticosteroids. Lung cancer patients are at greater risk for fatal infections. Infections increase morbidity in debilitated patients with solid tumors, are a frequent cause of hospital admission, and are associated with significant mortality.

Methylphenidate for depression in hospice practice: a case series

Psychostimulants such as methylphenidate have been used for depression in cancer patients. We report the successful use of methylphenidate to treat depression in 10 consecutive patients with advanced cancer. A rapid onset of effect was noted. Appetite, concentration, fatigue, and sedation also improved in some persons. No severe side effects were noted.

Hydrocodone for cough in advanced cancer

Cough is a common symptom in advanced cancer. Hydrocodone is the antitussive of choice in our palliative medicine inpatient unit. We reviewed the pharmacy records for the use of hydrocodone for all cancer admissions to our unit from May 1996 to December 1998. Median treatment duration with hydrocodone was three days (range 1-18). Median maximum daily dose was 15 mg (range 5-100), and median total dose during the hospital stay was 32 mg (range 5-455). Lung cancer as a primary cancer site was strongly related to the use of hydrocodone. The highest median duration of treatment (five days) was for esophageal cancer and the highest median maximum daily dose (35 mg) and total dose (75 mg) were for treating kidney cancer. This retrospective review provides information regarding the use of hydrocodone on the palliative medicine unit of the Cleveland Clinic Foundation. Controlled trials are needed to evaluate the efficacy and safety of hydrocodone for cough in advanced cancer.

Psychostimulants in supportive care

Psychostimulant medications have been used clinically and investigated in psychiatric populations, the medically ill, cancer patients and healthy people. This article discusses the pharmacology of dextroamphetamine, methylphenidate, pemoline (and other psychostimulants such as caffeine and ephedrine), their use in general medicine and cancer care, side effects, and abuse potential. Therapeutic use in children is addressed only insofar as it illustrates facets of their use in adults.

Ask the patient: a semi-structured interview study of quality of life in advanced cancer

The purpose of this exploratory study was to identify important aspects of quality of life for patients with advanced cancer Thirty patients with advanced cancer were interviewed in this qualitative study using a 23-question, face-to-face format. Questions were asked about affective, global, social, and power domains. Tape-recorded interviews were analyzed using computer data analysis software. Results indicated that patients expressed more positive feelings about their quality of life than expected. Gender differences were noted in responses in the affective, social, and power domains. Family was identified as an important component of quality of life.

Modern management of the cancer anorexia-cachexia syndrome

The cancer anorexia-cachexia syndrome is common, occurring in 80% of patients with advanced-stage cancer, and it is one of the most frequent causes of death in patients with cancer. It is a complex problem involving abnormalities in protein, carbohydrate, and fat metabolism. Tumors have both direct and indirect effects that result in anorexia and weight loss. The disease burden does not necessarily correlate with the degree of cachexia. In addition to the physical manifestations, the resulting abnormalities have a significant psychologic effect on patients and their families. Although there is no treatment to reverse the process, pharmacologic and nonpharmacologic measures can enhance food intake and improve quality of life.

Dual-echelon single-shot femtosecond spectroscopy

A dual-echelon technique for performing real-time pumpprobe spectroscopy with sub-100-fs temporal resolution is demonstrated. In a single laser shot, measurements at 400 different temporal delays are recorded to cover a total temporal range of 10 ps in 25-fs steps. Data from a glass sample and an explosive single crystal, each irradiated with intensity above the permanent damage threshold, are presented.

The genome sequence of Drosophila melanogaster

The fly Drosophila melanogaster is one of the most intensively studied organisms in biology and serves as a model system for the investigation of many developmental and cellular processes common to higher eukaryotes, including humans. We have determined the nucleotide sequence of nearly all of the approximately 120-megabase euchromatic portion of the Drosophila genome using a whole-genome shotgun sequencing strategy supported by extensive clone-based sequence and a high-quality bacterial artificial chromosome physical map. Efforts are under way to close the remaining gaps; however, the sequence is of sufficient accuracy and contiguity to be declared substantially complete and to support an initial analysis of genome structure and preliminary gene annotation and interpretation. The genome encodes approximately 13,600 genes, somewhat fewer than the smaller Caenorhabditis elegans genome, but with comparable functional diversity.

Use of an HBV-DNA hybridization assay in the evaluation of equivocal hepatitis B virus tests in solid organ donors

CONTEXT

Serological markers for the hepatitis B virus are routinely used in the evaluation of potential organ donors. However, serological tests can be associated with significant false or equivocal results and may not be indicative of the true risk of hepatitis B infection. Studies have recently questioned the significance of an isolated hepatitis B core antibody test in evaluating the suitability of solid organs for transplantation. The ability to detect hepatitis B virus DNA may prove useful when the diagnosis of hepatitis B infection is in doubt.

DESIGN

Serum samples from 16 donors with equivocal or positive hepatitis B core antibody and/or hepatitis B surface antigen serological screening tests were retrospectively tested for the presence of hepatitis B DNA. Any available follow-up data on the placement of organs from these donors was obtained.

RESULTS

One of the 16 (6.3%) donors tested positive for the presence of hepatitis B DNA, but organs from this donor were not recovered or transplanted. Follow-up on 14 organs recovered and transplanted from 6 donors in this group did not show clinical and/or laboratory evidence of hepatitis B infection in the recipients.

CONCLUSIONS

In our donor population, there was a low incidence (6.3%) of donors with equivocal or positive hepatitis B core antibody and/or hepatitis B surface antigen serological screening tests who subsequently demonstrated the presence of detectable hepatitis B DNA. Posttransplantation follow-up of the recipients of 14 recovered organs failed to demonstrate any cases of posttransplant hepatitis B infection.

The dying cancer patient

Cancer patients often die with serious unrelieved symptoms causing a distressing death for them and needless added suffering for their families. Many physicians have not been trained to care for the dying patient. This chapter reviews the common symptoms and describes the methods to control them and support the patient and family through this difficult time. These symptoms are so characteristic of the dying process that all physicians should recognize them, be skilled in providing appropriate care, and prepare for problems that may arise.

Common complications of advanced cancer

Complications due to cancer and its treatment are common and increase in incidence and severity as the disease progresses. Central nervous system complications affect 15% to 20% of patients, and up to 75% have bone metastases at some point during the disease process. Endocrine abnormalities include hypercalcemia, adrenal insufficiency, and inappropriate antidiuretic syndrome. Hematologic disorders, malignant effusions, and gastrointestinal (GI) problems may cause significant morbidity.